Edge bowl cooler



May 18, 1937. AMBER 2,080,594

EDGE BOWL COOLER Filed April 18, 1935 2 Sheets-Sheet l INVENTOR. JOHN Fir/5E2 I BY M1 98 A TTORNEYS.

May 18, 1937. J. AMBER EDGE BOWL COOLER Filed April 18, 1935 2 Sheets-Sheet 2 +JJ I IN VEN TOR. L/OHN l MBEiQ TTORNEYS.

Patented May 18, 1937 UNITED STATES EDGE. BOWL COOLER John Amber, Clarksburg, W. Va., assignor to Pittsburgh Plate Glass Company, a corporation of Pennsylvania Application April 18, 1935, Serial No. 16,965

2 Claims.

This invention relates to apparatus for drawing sheet glass and more particularly to improved means for cooling the area within and below an edge holding shield. It involves an improvement over the edge holding apparatus of the Halbach Patent No. 1,883,734. The apparatus of such patent is an effective and successful means for accomplishing the desired purpose, but the present invention provides certain advantages in the drawing of sheet glass.

One of the objects of this invention is to provide positive means for controlling the temperature of a definite portion of the molten glass contained under the edge holding shield. It is from this particular portion of the molten glass that the edge of the sheet is drawn and optimum temperature conditions must be maintained at all times to facilitate the drawing process. With abnormal temperatures the edge holding fingers cease to function and there is a tendency towards an inward movement of the edge of the sheet with gradual reduction of its width. Subnormal temperatures lead to vitrifaction and the process is necessarily interrupted until correct condi- 25 tions are again attained. By careful control of the temperature of this portion of the molten glass, a more perfect sheet of glass is formed and the speed of draw may be increased without affecting the final product.

30 A second object of the invention is to provide an independent mounting of the cooling means, which allows a wider range of adjustment than was heretofore available.

The objects and advantages of the invention 35 will be more clearly understood from the detailed description of one of the approved forms of the apparatus.

In the accompanying drawings:

Figure 1 is a plan view of a drawing tank showing the edge holding and directing members in position; Fig. 2 is a transverse section taken on line IIII of Fig. 1, showing one of the edge holding devices and support thereof in side elevation; and Fig. 3 is a perspective view, upon a larger scale, of the edge holding device and vertically adjustable cooler contained therein.

Referring to Fig. 2 of the drawings, a drawing tank I contains a molten bath of glass 2 in connection with a suitable melting tank, not shown. A glass sheet 3 is drawn from this molten bath 2 by any suitable drawing mechanism. Immediately under the center line of the sheet 3 is a slotted guiding bar 4 controlled through a lever arm 5 and a block 6 positioned at the end of a bar 4. A screw 1 actuates the lever arm 5 and permits of adjustment of the bar 4. This portion of the ap paratus constitutes no part of the present invention, being well known to the art.

The edge holding device in its preferred form, to which this invention is particularly directed, consists of a concave metallic plate 8 provided with a pair of forwardly projecting fingers 9. A cooling block to is positioned within the shield Band extends below the surface thereof through a slot l I provided in the metal shield. The plate 8 is secured to an adjustable supporting arm l2, which translates lateral movement to the shield by means of a ratchet gear l3 and vertical movement by the aid of a slot l4 and pin 15. The cooling block In is provided with conduits I6 and I! through which any suitable cooling medium may be circulated. The conduits also serve as means whereby the cooling block is attached to the supporting arm l2 through the agency of a plate l8 provided with guide fingers l9 and a set screw 20. This set screw 20 permits of vertical adjustment of the cooling block in relation to the edge shield, independently of the adjustment of the edge shield.

The fingers 9 perform their normal functions as in other edge holding devices of this type. They maintain proper size of the edge of sheet being drawn and at the same time exert a holding effect upon that edge, which serves to maintain a predetermined width constant.

The edge portions of the upwardly drawn glass sheet, from their source through the initial forming zone, pass through the edge forming and directing metallic members positioned at each side of the moving sheet. These metallic members may be secured in any desired position of adjustment by the clamping means. In this way the width of the glass sheet being drawn may be held constant at any predetermined degree. Since the cooling blocks extend below the surface of the edge shields, they provide means for regulating the temperature of a definite portion of the molten glass contained below the edge shields. This is accomplished by convection and there is no possibility of vitrifaction of the glass being drawn into the edge of the sheet. At the same time the main portions of the cooling blocks contained within the edge shields serve to cool the edge holding fingers and the edges of the glass sheet.

The novel features of this invention are contained in the different structure of the cooling block and the means provided whereby vertical adjustment of the cooling block in relation to and independently of the edge shield is secured.

ing a concave plate shield provided with an opening and having a pair of outwardly projecting fingers fitting around the edge of the sheet, means for cooling the area within and below the shield comprising a hollow block adjustable with relation to the shield partially surrounded by the concave shield and projecting below it through the opening provided therein, said block having a concave side adjacent the edge of the glass sheet being drawn but not in contact therewith, and

means for circulating a cooling medium through said block.

2. The combination with apparatus for drawing sheet glass from a molten pool, of means for maintaining a predetermined width of sheet comprising a concave plate shield provided with an opening and having a pair of outwardly projecting fingers fitting around the edge of the sheet, means for cooling the area within and below the shield comprising a cylinder vertically adjustable with relation to the shield and independently of the adjustment thereof partially surrounded by the concave shield and projecting below it through the opening provided therein, said cylinder having a concave side adjacent the edge of the glass sheet being drawn but not in contact therewith, and means for circulating -a cooling medium through said cylinder.

JOHN AMBER. 

